Answer:
The spring stretched by x = 13.7 cm
Explanation:
Given data
Mass = 3 kg
k = 120 
Angle 
= 34°
From the free body diagram
Force acting on the box = mg sin
⇒ F = 3 × 9.81 × 
⇒ F = 16.45 N ------- (1)
Since box is attached with the spring so a spring force also acts on the box.
= k x
= 120 
-------- (2)
The net force acting on the body is given by
Since acceleration of the box is zero so
Put the values from equation (1) & (2) we get
16.45 = 120
x = 0.137 m
x = 13.7 cm
Therefore the spring stretched by x = 13.7 cm
6. D
7. D
8. B
let me know if you need clarification
Answer:
<h2>18150 J</h2>
Explanation:
The kinetic energy of the car can be found by using the formula
m is the Mass
v is the velocity
From the question we have
We have the final answer as
<h3>18150 J</h3>
Hope this helps you
Net force on the car=F=4.8 x 10³ N
Explanation:
mass of car= 1.2 x 10³ Kg
initial velocity= Vi=0
Final velocity= Vf= 20 m/s
time = t= 5 s
Using kinematic equation,
Vf= Vi + at
20= 0 + a (5)
5 a=20
a= 20/5
a= 4 m/s²
Now force is given by F = ma
F= 1.2 x 10³ (4)
F=4.8 x 10³ N
Decreases, stays the same, increases.
The volume decreases because as air is cooled, the individual molecules collectively possess less kinetic energy and the distances between them decrease, thus leading to a decrease in the volume they occupy at a certain pressure (please note that my answer only holds under constant pressure; air, as a gas, doesn't actually have a definite volume).
The mass stays the same because physical processes do not create or destroy matter. The law of conservation of mass is obeyed. You're only cooling the air, not adding more air molecules.
The density decreases because as the volume decreases and mass stays the same, you have the same mass occupying a smaller volume. Density is mass divided by volume, so as mass is held constant and volume decreases, density increases.
