Answer:
wave length is 1.2m
Explanation:
since formula of wave length is v/f
v(speed of sound in air at stp is 300ms^-1)
f(frequency 250hertz)
then wave length is 300÷250 which give 1.2m
Answer:
due to the magnetic field
Explanation:
magnetic field is the same in the vacuum
Answer:
Tension in the supporting cable is = 4,866 N ≅4.9 KN
Explanation:
First of all, we need to understand that tension is a force, so the motion law
F = Ma applies perfectly.
From Newtons third law of motion, action and reaction are equal and opposite. This means that the force experienced by the elevator, is equal to the tension experienced by the spring.
Parameters given:
Mass of load = 1650 kg
Acceleration of load = ?
The acceleration of the load can be obtained by diving the change in velocity by the time taken. But we need to know the time taken for the motion to 41 m.
Time taken = distance covered / velocity
=
= 3.73 seconds
∴Acceleration = ( initial velocity - final velocity )/ time taken
Note: Final velocity is = 0 since the body came to a rest.
Acceleration =
= 2.95m/
Force acting on the cable = mass of elevator × acceleration of elevator
= 1650 × 2.95 = 4869.5 kg ≅ 4.9 KN
Answer:
The time for final 15 cm of the jump equals 0.1423 seconds.
Explanation:
The initial velocity required by the basketball player to be able to jump 76 cm can be found using the third equation of kinematics as

where
'v' is the final velocity of the player
'u' is the initial velocity of the player
'a' is acceleration due to gravity
's' is the height the player jumps
Since the final velocity at the maximum height should be 0 thus applying the values in the above equation we get

Now the veocity of the palyer after he cover'sthe initial 61 cm of his journey can be similarly found as

Thus the time for the final 15 cm of the jump can be found by the first equation of kinematics as

where symbols have the usual meaning
Applying the given values we get
