Answer:
8.85437 m/s
Explanation:
m = Mass of sphere = 5 kg
h = Vertical height = 4 m
g = Acceleration due to gravity = 9.80 m/s²
Applying conservation of energy we get




The sphere's speed when it reaches the bottom of the ramp is 8.85437 m/s
Answer:
Explanation:
Given

Motor reverse its direction when \omega =0



(b)





Answer:
Explanation:
Current drawn by electric heater = power/volt =1500/120 = 12.5 A.
current drawn by hair drier at 600 watt = 600/120 =5 A
current drawn by hair drier at 900 watt = 900/120 = 7.5 A.
Total current drawn by heater and hair drier used at 900 watt
= 12.5 + 7.5 = 20 A
Breaking current =20 A
So fuse will trip at this point .
Explanation:
Let the speeds of father and son are
. The kinetic energies of father and son are
. The mass of father and son are 
(a) According to given conditions, 
And 
Kinetic energy of father is given by :
.............(1)
Kinetic energy of son is given by :
...........(2)
From equation (1), (2) we get :
..............(3)
If the speed of father is speed up by 1.5 m/s, so the ratio of kinetic energies is given by :


Using equation (3) in above equation, we get :

(b) Put the value of
in equation (3) as :

Hence, this is the required solution.
Answer:
θ=180°
Explanation:
The problem says that the vector product of A and B is in the +z-direction, and that the vector A is in the -x-direction. Since vector B has no x-component, and is perpendicular to the z-axis (as A and B are both perpendicular to their vector product), vector B has to be in the y-axis.
Using the right hand rule for vector product, we can test the two possible cases:
- If vector B is in the +y-axis, the product AxB should be in the -z-axis. Since it is in the +z-axis, this is not correct.
- If vector B is in the -y-axis, the product AxB should be in the +z-axis. This is the correct option.
Now, the problem says that the angle θ is measured from the +y-direction to the +z-direction. This means that the -y-direction has an angle of 180° (half turn).