For the first one: A falling object has higher gravitational potential energy and as it falls this decreases but kinetic energy increases. As the object hits the floor, energy is transferred to heat and sound.
42*9.8*12= 4939.2
Kinetic energy = 4939.2 OR 4939
To find the final speed use the kinetic energy formula;
Ek = 1/2 MV2
4939=1/2*42*v2
V2= 4939 divided by (1/2 * 42)
V2= 4939 / 21
V2= 235.1904761904762
Find square root
V= 15.3359211067
= 15.
Reach the ground at 15m s -¹
Note:
Formula To calculate kinetic energy:
Ek = 1/2 MV2
Ek= kinetic energy of an object
M= mass of object
V= velocity/speed of object
Answer:
23 m/s
Explanation:
First, find the time it takes for the car to fall 40 meters.
y = y₀ + v₀ t + ½ at²
0 = 40 + (0) t + ½ (-9.8) t²
0 = 40 − 4.9 t²
t = 2.89 s
Next, find the velocity needed to travel 65 meters in that time.
x = x₀ + v₀ t + ½ at²
65 = 0 + v₀ (2.89) + ½ (0) (2.89)²
v₀ = 22.75 m/s
Rounding to two significant figures, the car's initial speed was 23 m/s.
Answer:
a)
125.6 rad/s
b)
25.12 rad/s²
Explanation:
a)
t = time required by the fan to get up to final operating speed = 5 sec
w = final operating rotational speed = 1200 rpm
we know that :
1 revolution = 2π rad
1 min = 60 sec
w =
w =
w = 125.6 rad/s
b)
w₀ = initial angular speed = 0 rad/s
α = angular acceleration
using the equation
w = w₀ + α t
125.6 = 0 + α (5)
α = 25.12 rad/s²
weathering refers to the actual breaking part of the rock or soil. deposition happens when the weathered and eroded material is deposited and finally comes to a stand still.
C iron oxide hope this helps