The change in mechanical energy caused by the dissipative resistance force is equal to, difference between the potential energy and kinetic energy of the object.
Potential energy of the object, P.E = mgh
m is mass of the object = 10 kg
g is acceleration due to gravity = 9.8 m/s²
h= height from which it is dropped =50 m
Substituting the value we get,
P.E = 10×9.8×50 = 4900 J
Kinetic energy of the object, K.E = 
v is the velocity of the object = 26 m/s²
K.E = (1/2)×10×(26)²
= 3380 J
Change in mechanical energy caused by dissipative force = P.E ₋ K.E
= 4900 ₋ 3380 = 1520 J
The answer would be false
Answer:
1) 10.1 s 2) 909 m 3) 90.0 m/s 4) -99m/s 5) just over the bomb.
Explanation:
1)
- In the vertical direction, as the bomb is dropped, its initial velocity is 0.
- So, we can find the time required for the bomb to reach the earth, applying the following kinematic equation for displacement:
- where Δy = -500 m (taking the upward direction as positive).
- a=-g=-9.8 m/s²
- Replacing these values in (1), and solving for t, we have:
- The time required for the bomb to reach the earth is 10.1 s.
2)
- In the horizontal direction, once released from the helicopter, no external influence acts on the bomb, so it will continue moving forward at the same speed. that it had, equal to the helicopter.
- As the time must be the same for both movements, we can find the horizontal displacement just as the product of this speed times the time, as follows:
3)
- The horizontal component of the bomb's velocity is the same that it had when left the helicopter. i.e. 90 m/s.
4)
- In order to find the vertical component of the bomb's velocity just before it strikes the earth, we can apply the definition of acceleration, remembering that v₀ = 0, as follows:
5)
- If the helicopter keeps flying horizontally at the same speed, it will be always over the bomb, as both travel horizontally at the same speed.
- So, when the bomb hits the ground, the helicopter will be exactly over it.
Answer:
Total work done is 2606.08 J.
Explanation:
Given :
Mass of box , m = 23 kg .
Force applied , F = 100 N .
Angle from horizon , 
.
Coefficient of kinetic friction , 
.
Distance travelled by box , d = 34 m .
Now ,
Total work done = work done by boy + work done by friction.
Hence , this is the required solution.
Answer and Explanation:
Using Gauss's law,
If r>a
then charge enclosed in all the three cases is same as Q.
So Electric field for all three is same.
So {1,1,1}.
(b) r<a,
Charge enclosed in case of shell is zero since all charge is present on the surface. So E = 0.
Charge enclosed by incase of point charge is Q.
Charge enclosed in case of sphere is Qr3/a3 which is less than Q.
So ranking {2,3,1}
