Answer:
Final Speed of Dwayne 'The Rock' Johnson = 15.812 m/s
Explanation:
Let's start out with finding the force acting downwards because of the mass of 'The Rock':
Dwayne 'The Rock' Johnson: 118kg x 9.81m/s = 1157.58 N
Now the problem also states that the kinetic friction of the desk in this problem is 370 N
Since the pulley is smooth, the weight of Dwayne Johnson being transferred fully, and pulls the desk with a force of 1157.58 N. The frictional force of the desk is resisting this motion by a force of 370 N. Subtracting both forces we get the resultant force on the desk to be: 1157.58 - 370 = 787.58 N
Now lets use F = ma to calculate for the acceleration of the desk:
787.58 = 63 x acceleration
acceleration = 12.501 m/s
Finally, we can use the motion equation:
here u = 0 m/s (since initial speed of the desk is 0)
a = 12.501 m/s
and s = 10 m
Solving this we get:
Since the desk and Mr. Dwayne Johnson are connected by a taught rope, they are travelling at the same speed. Thus, Dwayne also travels at 15.812 m/s when the desk reaches the window.
Initial velocity (u) = 0 m/s
Final velocity (v) = 25 m/s
time taken (t) = 10s
acceleration (a) = ?
Now,
Acceleration is rate of change of velocity, so formula is
a = (v - u)/t
a = (25 - 10)/10
a = 15/10
a = 1.5 m/(s^2)
Use this value of a.
Answer:
time taken with speed 23 km/h will be 1.8 hours or 1 hour 48 minutes
Explanation:
Given:
Time is inversely proportional to the speed
mathematically,
t ∝ (1/r)
let the proportionality constant be 'k'
thus,
t = k/r
therefore, for case 1
time = 3 hr
speed = 14 km/hr
3 = k/14
also,
for case 2
let the time be = t
r = 23 km/h
thus,
we have
t = k/23
on dividing equation 2 by 1
we get
or
or
t = 1.8 hr = or 1 hour 48 minutes ( 0.8 hours × 60 minutes/hour = 48 minutes)
Answer:
F=1.65 x 10²⁶ N
Explanation:
Given that
Distance ,R= 3.34 x 10¹² m
Mass m₁= 2.78 x 10³⁰ kg
Mass ,m₂= 9.94 x 10³⁰ kg
we know that gravitational force F given as
G=Constant
G=6.67 x 10⁻¹¹ Nm²/kg²
Now by putting the values
F=1.65 x 10²⁶ N
Therefore the force between these two mass will be 1.65 x 10²⁶ N.
Answer:
Sample Response: If temperature and surface area increase, then the time it takes for sodium bicarbonate to completely dissolve will decrease, because increasing both factors increases the rate of a chemical reaction.
Explanation:
