A 59 kg sprinter, starting from rest, runs 47 m in 7.0 s at constant acceleration.?
What is the sprinter's power output at 2.0 s, 4.0 s, and 6.0 s?
Instantaneous Power is the force times velocity
P = Fv
Because the acceleration is constant, the force will be constant as well
F = ma
P = mav
for constant acceleration, the velocity at each time is found using
v = at
P = ma(at) = ma²t
find the acceleration using kinematic equation
s = ½at²
a = 2s/t²
a = 2(47) / 7.0²
a = 1.918 m/s²
P(2.0) = 59(1.918²)2.0 = 434.25 W = 0.43 kW
P(4.0) = 59(1.918²)4.0 = 868.51 W = 0.87 kW
P(6.0) = 59(1.918²)6.0 = 1302.76 W = 1.3 kW
I hope this helped.
Answer:
Explanation:
The Planck Eistein relation, states that the energy of a photon is proportional to its frequency:
h is the Plank constant.The frequency of a photon is defined as the speed of light over its wavelength:
Replacing (2) in (1):
Answer:
Explanation:
Acceleration is the change in velocity with respect to time.
Acceleration = change in velocity/Time
Acceleration = final velocity - initial velocity/Time
Given initial velocity = 10m/s
Final velocity = 20m/s
Time taken = 4s
Acceleration = 20-10/4
Acceleration = 10/4
Acceleration =2.5m/s²
For the second part of the question:
Given parameters
initial velocity = 15m/s
acceleration = -3m/s²
time = 4seconds
a = v-u/t
-3 = v-15/4
cross multiply
-12 = v-15
add 15 from both sides
-12+15 = v-15+15
3 = v
<em>Hence the final velocity of the car is 3m/s</em>
Answer:
2.064 N.m
Explanation:
Torque: This is the force that act on a system, which tends to cause rotation or twisting. The S.I unit of Torque is N.m
Torque is represented mathematically as,
T = F×d........................ Equation 1
Where T = Torque, F = Force, d = perpendicular distance.
Given: F = 4.8 N, d = 0.43 m.
Substitute into equation 1
T = 4.8×0.43
T = 2.064 N.m
Hence the Torque produced = 2.064 N.m
