The equation to be used is for the rectilinear motion at constant acceleration:
x = v₀t + 0.5at²
a = (v-v₀)/t
where
x is distance
v and v₀ is the final and initial velocity
t is time
a is acceleration
Because the acceleration is decelerating, that would be reported as -7.5 m/s². Substituting,
-7.5 = (0 - v₀)/t
v₀ = 7.5 t --> eqn 1
x = v₀t + 0.5at²
60 = (7.5t)(t) + 0.5(-7.5)(t²)
Solving for t,
t = 4s
Thus,
v₀ = 7.5 m/s² * 4s
v₀ = 30 m/s
Speed = Distance/ Time
Speed = 400 / 4
Speed = 100 km/hr.
100 km per hour.
A. Equal and opposite forces
Explanation:
History law states that for every action (force) in nature there is an equal and opposite reaction. In other words, if object A exerts a force on object B, then object B also exert an equal and opposite force on object A
Answer:
U = 56877.4 J
Explanation:
The potential energy of a body is that which it possesses because it is located at a certain height above the surface of the earth and can be calculated using the following formula:
U = mgh Formula (1)
Where:
U is the potential energy in Joules (J)
m is the mass of the body in kilograms (kg)
g is the acceleration due to gravity (m/s²)
h is the height at which the body is found from the surface of the earth in meters (m)
Data
m= 81.4 kg
g= 9.8 m/s²
h = 71.3 m
Potential energy of Sean and the parachute at the top of the tower
We replace data in the formula (1)
U = m*g*h
U = (81.4 kg)*(9.8 m/s²)*(71.3 m)
U = 56877.4 N*m
U = 56877.4 J
Answer:
A
Explanation:
This is because distance traveled (i.e. displacement) is the integral of the velocity function, and velocity is the first derivative of the displacement function. To put this in perspective, the area bounded by a curve can be found by taking the integral of the equation of the curve, taking values on the x-axis as limits.
