Answer:
11760J
Explanation:
Given parameters:
Height of hill = 30m
Weight = 40kg
Unknown:
Gravitational potential energy = ?
Solution:
To find the gravitational potential energy, it is the energy due to the position of a body;
G.PE = mgh
m is the mass
g is the acceleration due to gravity
h is the height
Now insert the parameters and solve;
G.PE = 40 x 9.8 x 30 = 11760J
Answer: 477W
Explanation:
Given the following :
Mass (m) = 7.3kg
Initial Velocity (u) = 0
Final velocity (v) = 14m/s
time (t) = 1.5s
Power = workdone (W) / time (t)
The workdone can be calculated as the change in kinetic energy (KE) :
Recall ;
KE = 0.5mv^2
Therefore, change in KE is given by:
0.5mv^2 - 0.5mu^2
Change in KE = 0.5(7.3)(14^2) - 0.5(7.3)(0^2)
Change in KE = 715.4J
Therefore ;
Average power = Workdone / time
Workdone = change in KE = 715.4N
Average power = 715.4 / 1.5
Average power = 476.93333 W
= 477W
Answer:
D
D
C
C
Explanation: BRAINLIEST ME
The hotter an object is, the more infrared radiation it emits. Infrared radiation is a type of electromagnetic radiation, which involves waves rather than particles. This means that, unlike conduction and convection, radiation can even pass through the vacuum of space.
The final position of the car is 385 m.
Explanation:
We know the formula :
s =

where,
s = distance
u = initial velocity = 5.1 m/s
t = time taken = 14 sec
a = acceleration = 3.2 m/
Solving:
s = 5.1* 14 +
* 3.2 * 
∴ s = 385 m
Hence the final position of the car is 385 m.