Answer:
a = - 1.47 [m/s²], descending or going down
Explanation:
To solve this problem we must use Newton's second law which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
∑F = Forces applied [N]
m = mass = 10 [kg]
a = acceleration [m/s²]
Let's assume the direction of the upward forces as positive, just as if the movement of the box is upward the acceleration will be positive.
By performing a summation of forces on the vertical axis we obtain all the required forces and other magnitudes to be determined.
where:
g = gravity acceleration = 9.81 [m/s²]
N = normal force measured by the scale = 83.4 [N]
Now replacing:
The acceleration has a negative sign, this means that the elevator is descending at that very moment.
Answer: τ = 0
Explanation:
At constant angular velocity there is no angular acceleration therefore no torque.
τ = Iα
Answer:
Below
Explanation:
To find the wave speed of a wave you can use this formula :
wavespeed (v) = (frequency) x (wavelength λ)
Plug in our values :
v = (10Hz) x (2m)
v = 20 m/s
Hope this helps!
Answer:
t=0.417s
Explanation:
After the ball hits the racket it is in freefall(assume air resistance as negligible)
so a=-g
use
x-x0=v0t+1/2at^2
Plug in givens
20=50t-4.9t^2
Solve quadratic equation using quadratic formula
t= 0.417 seconds, (the other answer is extraneous because it is too big because in 1 second, the ball travels 50 meters)
Answer:
Explanation:
The magnetic field B inside long solenoid with current I is given as
where
N is number of turn of solenoids = 1140 turns
I is current that passes through solenoid
L is length along which current pass = 0.350 m
plugging value to get required value of current