Lv 1135 points

# matt c

• ### I really need help on this physics problem!!?

A 295 kg piano slides 4.3 m down a 30 degree incline and is kept from accelerating by a man who is pushing back on it parallel to the incline. the effective coefficient of kinetic friction is 0.40. A.) What is the force exerted by the man? B.) What is the work done by the man on the piano? C.) What is the work done by the friction force? D.)What is the work done b the force of gravity? E.) What is the net work done on the piano?

• ### Average force?

A baseball (m= 145 g) traveling 50m/s moves a fielders glove backward 30 cm when the ball is caught. What was the average force exerted by the ball on the glove?

• ### Phyics Help?

A 845 N crate rests on the floor. How much work is required to move it at constant speed 4.4 m along the floor against a friction force of 180 N? Also how much work is required to move it at constant speed 4.4 m vertically?

• ### Magnitude and direction of Gravitational Force?

Four 1.8 kg masses are located at the corners of a square 1.00 m on each side. Find the magnitude and direction of the gravitational force on a fifth 1.8 kg mass placed at the midpoint of the bottom side of the square.

• ### Physics question: Speed?

A projectile is fired at an upward angle from the top of a 105 m cliff with a speed of 185 m/s. What will be its sped when it strikes the ground below?(Use conservation of energy and neglect air resistance.)

• ### Potential energy?

A spring has a spring constant, k, of 439N/m. How much must this spring be stretched to store 25 J of potential energy?

• ### Net work done on box?

A box of mass 6.0 kg is accelerated from rest by a force actoss a floor at a rate of 2.0 m/s^2 for 7.0 s. what is the net work done on the box?

• ### Initial Speed?

Police lieutenants, examining the scene of an accident involving two cars, measure the skid marks of one of the cars, which nearly came to a stop before colliding,to be 83 m long. The coefficient of kinetic friction between rubber and the pavement is about 0.90. Estimate the intial speed of that car assuming a level road.

• ### Friction Force?

A 23.0 kg box is released on a 39.0 degree incline and accelerates down the incline at 0.273 m/s^2. Find the friction Force impeding its motion, and how large is the coefficient of friction?

• ### Force of Gravity?

Calculate the force of gravity, toward the earth, on a spacecraft 6400 km (1 Earth radii) above the Earth's surface if its mass is 1000 kg.

• ### physics question?

What is the distance from the Earth's center to a point outside the Earth where the gravitational acceleration due to the Earth is 1/34 of its value at the Earth's surface?

• ### Force Questions involving Helicopters?

A 6510 kg helicopter accelerates upward at 0.61 m/s^2 while lifting a 1190 kg frame at a construction site. What is the lift force exerted by the air on the helicopter rotors? What is the tension in the cable (ignore mass) that connects the frame to the helicopter? and What force does the cable exert on the helicopter?

• ### Minimum speed?

At what minimum speed must a roller coaster be traveling when upside down at the top of a circle so that the passengers will not fall out? Assume a radius of curvature of 8.2 m.

• ### Friction Force?

A 21.0kg box is released on a 37.0 degree incline and accelerates down the incline at 0.268 m/s^2. Find the friction force impeding its motion (N), and what is the coefficient of kinetic friction?

• ### Maximum and Minimum Force?

An elevator with the mass of 4175 kg is to be designed so that the maximum acceleration is 0.0800 g.

What is the maximum force the motor should exert on the supporting cable? The minimum?

• ### Kinetic friction?

a box is given a push so that it slides across the floor. How far will it go, given that the coeffficient of kinetic friction is 0.19 and the push imparts an initial speed of 4.1 m/s?

• ### Maximum speed?

a 0.40 kg ball, attached to the end of a horizontal cord, is rotated in a circle of radius 1.4 m on a frictionless horizontal surface. If the cord will break when the tension in it exceeds 57 N, what is the maximum speed the ball can have?