A 700 kg dragster accelerates from rest to a final speed of 120 m/s in 400 m (about a quarter of a mile) and encounters an average frictional force of 1200 N. What is its average power output in watts and horsepower of the car engine? a) watts=  b) horsepower=

Problem 7: Rescue workers lower a sled and injured ice climber, with a combined mass of 95 kg, down a 60° slope at a constant speed as shown in the diagram. The coefficient of kinetic friction between the sled and the snow is 0.1. Suppose the sled is lowered 30 m along the hillside. a) How much work is done by friction as the sled/climber moves along the hill? b) How much work is done by the gravitational force as the sled/climber moves along the hill? c) How much work is done by the tension force in the rope as the sled/climber moves along the hill? d) What is the net work done on the sled/climber? 60° W T

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Make an order-of-magnitude estimate of the power a car engine contributes to speeding the car up to highway speed. In your solution, state the physical quantities you take as data and the values you measure or estimate for them. The mass of a vehicle is often given in the owner’s manual.

You push on a block of mass m a frictionless table from rest to a speed v in a time t. What is your average power output? a) – mv^2/2t b)+ mv^2/2t c) mv/t d) zero

At Schlitterbahn, a 75.0 kg person rides a 12.0 m high water slide. If dissipative forces do -6.25 x 10³ J on the rider as they go from rest at the top of the ride to the bottom, then what is the speed of the rider at the bottom of the slide? Include a diagram of the situation and indicate the mechanical energy at both the top and at the bottom of the slide.

A 7.80-g bullet moving at 530 m/s penetrates a tree trunk to a depth of 4.50 cm.  (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

A 600 kg dragster accelerates from rest to a final speed of 120 m/s in 400 m (about a quarter of a mile) and encounters an average frictional force of 1200 N. What is its average power output in watts and horsepower of the car engine? ______ W ______ hp

A 7.80-g bullet moving at 560 m/s penetrates a tree trunk to a depth of 5.80 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the frictional force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment it stops moving.

A 7.80-g bullet moving at 470 m/s penetrates a tree trunk to a depth of 6.50 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Assuming the friction force is constant, determine how much time elapses between the moment the bullet enters the tree and the moment in stops moving.