Answer:
The total mechanical energy is the sum of kinetic and potential energies: E = K + U. The law of conservation of total mechanical energy states that the sum of the kinetic energy and potential energy is constant in time.
Well you of course have different kinetic energies with the two speeds.
Kinetic energy = (1/2)*mass*velocity^2
The vehicle's mass is the same in both cases, so we can ignore that as well as 1/2 since it's a constant.
So we have (30)^2 vs (60^2)
which is 900 vs 3600
So having 60 mph compared to 30 mph is 4 times the kinetic energy.
The answer is 111.
Using Newton's Second Law, F=ma, plugging known values in we get:
F = (79kg)(1.4m/s^2) = 110.6N ≈ 111N
Answer:
13.3 m/s
Explanation:
The motion is a projectile motion. The horizontal distance travelled, called the range, is given by
u is the initial speed, 
is the angle with the horizontal and g is acceleration of gravity.
