Answer:
25 m/s
Explanation:
This is a uniformly accelerated motion, so the velocity at time time is given by
where is the initial velocity and a is the acceleration.
In this problem, the initial velocity is zero: v0=0. The acceleration is the component of the gravitational acceleration projected along the direction of motion, so
Therefore, the velocity after t=10 s will be
The magnification of the ornament is 0.25
To calculate the magnification of the ornament, first, we need to find the image distance.
Formula:
- 1/f = u⁻¹+v⁻¹.................... Equation 1
Where:
- f = Focal length of the ornament
- u = image distance
- v = object distance.
make u the subject of the equation
- u = fv/(f+v)................ Equation 2
From the question,
Given:
Substitute these values into equation 2
- u = (12×4)/(12+4)
- u = 48/16
- u = 3 cm.
Finally, to get the magnification of the ornament, we use the formula below.
- M = u/v.................. Equation 3
Where
- M = magnification of the ornament.
Substitute these values above into equation 3
Hence, The magnification of the ornament is 0.25
Answer:
Friction is the main factor which reduces the efficiency of a simple machine. Efficiency of a simple machine can be increased by reducing the friction. But oiling and greasing the machine is a useful way to increase the efficiency of a machine.
Explanation:
Because all machines lose input work to friction, one way to improve the efficiency of a machine is by reducing friction. Oil is used to reduce friction between the moving parts of car engines. The use of oil makes engines more efficient. Another machine that loses input work is a bicycle.
Answer:
Inducted Magnetic field will be toward from you
Inducted current direction will be counter clockwise.
Explanation:
Lenz's law states that the direction of the current induced in a wire by a changing magnetic field is such that the magnetic field created by the induced current opposes the initial changing magnetic field.
So if the field begins to decrease, the induced magnetic field would try to stop this, so its direction will be the same as the magnetic field, toward from you.
This induced magnetic field is produced by the current in the wire. If the inducted magnetic field will be toward you, the right hand rule says that the direction from the inducted current will be counter clockwise.