# Physics Work Magnitude HELP!!!!?

Given that the tree doesn’t move, and the car comes to rest:

a.) Find the amount of work done by the tree on the car as the front of the car crashes into the tree, but use m = 2525 kg instead.

b.) Find the magnitude of the force that pushed in the front of the car by 42.0 cm

### 2 Answers

- billrussell42Lv 71 month agoFavorite Answer
Kinetic Energy in J if m is in kg and V is in m/s

KE = ½mV²

KE = ½2525(12)² = 181800 J

Find the magnitude of the force that pushed in the front of the car by 42.0 cm

assuming this means the car came to a stop in 42 cm with constant acceleration

v² = v₀² + 2ad

0 = (12)² + 2a(0.42)

0.84a = –144

a = –176 m/s²

F = ma = 2525 x 176 = 443000 N

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- A Yahoo UserLv 71 month ago
energy = 1/2 m v-squared

we need to know how long the crash took (from beginning of crash to end of crash)

or the rate of deceleration

in order to calculate the force

- DeShawn1 month agoReport
Please submit answer with work instead of instructing what to do.

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