Answer:
1000 N
Explanation:
First, we need to find the deceleration of the running back, which is given by:

where
v = 0 is his final velocity
u = 5 m/s is his initial velocity
t = 0.5 s is the time taken
Substituting, we have

And now we can calculate the force exerted on the running back, by using Newton's second law:

so, the magnitude of the force is 1000 N.
Answer:
3. Mowing the lawn
Explanation:
Aerobic exercise is any type of cardiovascular conditioning.
Mowing the lawn is the only thing that is actively moving.
Explanation:
Constant speed means that the object is covering equal distance in equal interval of time. The motion is called uniform motion for such case. In this problem, it is given that an object is moving with a constant speed of 8 m/s. It means that it does not change its speed. It is moving with a single speed constantly.
We can say that it moves 8 meters every second or 800 cm every second.
The answer is C.
The Kinetic energy which was exerted and experience pulling the string of a bow is kept as a potential energy at the end of the arrow in contact with the string. Once release from aim at stationary position the potential energy is again transformed.
Answer:
50.3N
Explanation:
Work done = force x distance
422J. = force x 8.39m
÷8.39 both side to get force
Force is 50.3N to 1 d.p.
Check:
50.3 x 8.39=422.017J
Same as 422J to 1 d.p