Answer:
792 J
Explanation:
The total energy of the ball is E = U + K where U = potential energy = mgh and K = kinetic energy = 1/2mv²
E = mgh + 1/2mv² where m = mass of ball = 2.0 kg, g = acceleration due to gravity = 9.8 m/s², h = height of building = 20.0 m, v = initial velocity of ball = 20.0 m/s.
So, substituting the values of the variables into E, we have
E = mgh + 1/2mv²
= 2.00 kg × 9.8 m/s² × 20.0 m + 1/2 × 2.00 kg × (20.0 m/s)²
= 392 J + 400 J
= 792 J
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answers
velocity = 7 m/s
tension = 7.644 N
set up equation for velocity
because energy is conserved, the change in potential energy as the potato drops is the same as the change in kinetic energy
U = K
mgh = m/2
gh = /2
= 2gh
v =
values
g = 9.8 m/s^2
h = 2.5 m (change in vertical distance)
plug in values and solve
v =
v =
v = 7 m/s
set up equation for tension
at the lowest point, tension (directly upward) acts in the opposite direction of weight (directly downwards) so
∑F = T - mg
since the potato is in circular motion, the net force is equal to centripetal force
∑F = m/r
∑F = T - mg = m/r
T - mg = m/r
T = mg + m/r
T =
values
m = 0.26 kg
g = 9.8 m/s^2
v = 7 m/s
r = 2.5m
plug in values and solve
T =
T =
T = 7.644 N
1. Answer;
Acceleration is;
-2.46m/s²
Explanation;
The initial velocity is 8.6 m/s, the final velocity = 0 m/s
The time is 3.5 seconds
Using the equation;
V =U + at
but V =0 , -U = at
a = -U/t = -8.6 /3.5
= -2.457 m/s²
= -2.46 m/s² (2 d.p)
2. Answer;
The distance is ;
=15.1 m
Solution;
a = -2.46 m/s², v=0 and U = 8.6 m/s
Using the equation;
V² = U² +2as (where s is the distance)
but v =0, thus, s =U²/2a
= -8.6²/ 2(-2.46)
= -73.96 /-4.92
= 15 .1 m (1 d.p)
Answer:
17.64 Newtons
Explanation:
In order to find the weight of an object we take the mass in kilograms and multiply it by the gravitational constant (9.8), which is 1.8 * 9.8 = 17.74 Newtons.