Explanation:
Given parameters:
Initial velocity = 72km/hr
Final velocity = 0km/hr
Time taken = 25s
Unknown:
Acceleration = ?
Solution:
To solve this problem, convert km/hr to m/s;
1000m = 1km
3600s = 1hr
72km/hr;
1km/hr = 0.278m/s
72km/hr = 0.278 x 72 = 20.02m/s
Acceleration is the change in velocity divided by the time taken;
Acceleration =
Acceleration = = -0.8m/s
The car is actually decelerating at a rate of 0.8m/s
Answer:
V=15.3 m/s
Explanation:
To solve this problem, we have to use the energy conservation theorem:
the elastic potencial energy is given by:
The work is defined as:
this work is negative because is opposite to the movement.
The gravitational potencial energy at 2.5 m aboves is given by:
the gravitational potential energy at the ground and the kinetic energy at the begining are 0.
Answer:
The tension in the string is 16.24 N
Explanation:
Given;
mass of the sphere, m = 1.55 kg
initial velocity of the sphere, u = 2.81 m/s
final velocity of the sphere, v = 4.60 m/s
duration of change in the velocity, Δt = 2.64 s
The tension of the string is calculated as follows;
T = 1.55(0.678 + 9.8)
T = 1.55(10.478)
T = 16.24 N
Therefore, the tension in the string is 16.24 N