Answer:
B). to the right
Explanation:
Since the direction of magnetic field is into the page
So here we know that

now the velocity is from bottom to top
so we have

now the force on the moving charge is given as

now we have


so force will be towards Right
Answer:
B. τ = 16 Nm
Explanation:
In order to find the torque exerted by the weight attached to the heel of man's foot, when his leg is stretched out. We use following formula:
τ = Fd
here,
τ = Torque = ?
F = Force exerted by the weight = Weight = mg
F = mg = (4 kg)(10 m/s²) = 40 N
d = distance from knee to weight = 40 cm = 0.4 m
Therefore,
τ = (40 N)(0.4 m)
<u>B. τ = 16 Nm</u>
Answer:
So length of pendulum is 143.129 m
Explanation:
We have given period of simple pendulum is 2 sec
We have to find the length of simple pendulum
Let the length of pendulum is l
Acceleration due to gravity
is
Time period is given by 
So 

Squaring both side

l =143.129 m
So length of pendulum is 143.129 m
Answer:
Explanation:
Given
Minute hand length =16 cm
Time at a quarter after the hour to half past i.e. 1 hr 45 min
Angle covered by minute hand in 1 hr is 360 and in 45 minutes 270


(c)For the next half hour
Effectively it has covered 2 revolution and a quarter

angle turned 
(f)Hour after that
After an hour it again comes back to its original position thus displacement is same =25.136
Angle turned will also be same i.e. 
Answer:
Tension in the string at this position: 3.1 N.
Explanation:
Convert the radius of the circle to meters:
.
What's the net force on the object?
The object is in a circular motion. As a result,
,
where
is the net force on the object,
is the mass of the object,
is the velocity of the object, and
is the radius of the circular motion.
For this object,
.
The output unit of net force should be standard if the unit for mass, velocity, and radius are all standard. The net force shall always point towards the center. In this case the net force points downwards.
What are the forces on this object?
There are two forces on the object at this moment:
- Weight,
, which points downwards.
. - Tension,
, which also points downwards. The size of the tension force needs to be found.
What's the size of the tension force?
Gravity and tension points in the same direction. The size of their resultant force is the sum of the two forces. In other words,
.
.
All three values in this question are given with two sig. fig. Round the value of
to the same number of significant figures.