asdek asked in Science & MathematicsPhysics · 9 months ago

# 2 Physics Quiz Questions Help Please?

) At t = 0 a stone is thrown with an initial velocity, vi = 20 m/s at an angle, θi = 53O above the horizontal. (Take g = 10 m/s2, cos53O = 0.6, sin53O = 0.8,). Find the horizontal and vertical components of its position (x, y) and velocity (vx, vy) at the height point and at t = 3 s.

4- a) A block, M = 5 kg starts from rest and moves down the inclined plane making angle θ = 37O with the horizontal. The kinetic friction force acting on the block is, fk = 10 N, see the figure. (a) Draw the free body diagram and find the acceleration of the block and (b) Find the normal force and the coefficient of kinetic friction µk between the block and the inclined surface (cos37O = 0.8, sin37O = 0.6, g = 10 m/s2).

Relevance
• 9 months ago

vx = 20 * 0.6 = 12 m/s

vy = 20 * 0.8 = 16 m/s

During the 3 seconds, the vertical component of the stone’s velocity will have an acceleration of -10 m/s^2

vy = 16 + -10 * 3 = -14 m/s

(12,-14)

4- a)

The net force is the component of the force that is parallel minus the friction force.

Force parallel = m * g * sin θ = 50 * 0.6 = 30 N

Normal force = m * g * cos θ = 50 * 0.8 = 40 N

Ff = μ * 40

μ * 40 = 10

μ = 0.25

Net force = 30 – 10 = 20 N

a = 20 ÷ 5 = 4 m/s^2

I hope this is helpful for you.

• asdek9 months agoReport

Thanks a bunch!