Answer:
5 mg, 
Explanation:
First of all, let's rewrite the mass in grams using scientific notation.
we have:
m = 0.005 g
To rewrite it in scientific notation, we must count by how many digits we have to move the dot on the right - in this case three. So in scientific notation is
If we want to convert into milligrams, we must remind that
1 g = 1000 mg
So we can use the proportion
and we find
Answer:
The gravitational force exerted on the object is 75 N (answer D)
Explanation:
Hi there!
The gravitational force is calculated as follows:
F = m · g
Where:
F = force of gravity.
m = mass of the object.
g = acceleration due to gravity (unknown).
For a falling object moving in a straight line, its height at a given time can be calculated using the following equation:
y = y0 + v0 · t + 1/2 · a · t²
Where:
y = position at time t.
y0 = initial position.
v0 = initial velocity.
t = time.
g = acceleration due to gravity.
Let´s place the origin of the frame of reference at the point where the object is released so that y0 = 0. Let´s also consider the downward direction as negative.
Then, after 2 seconds, the height of the object will be -30 m:
y = y0 + v0 · t + 1/2 · g · t²
-30 m = 0 m + 0 m/s · 2 s + 1/2 · g · (2 s)²
-30 m = 1/2 · g · 4 s²
-30 m = 2 s ² · g
-30 m/2 s² = g
g = -15 m/s²
Then, the magnitude of the gravitational force will be:
F = m · g
F = 5 kg · 15 m/s²
F = 75 N
The gravitational force exerted on the object is 75 N (answer D)
Have a nice day!
Answer:
a) 36 m
b) 64 m
Explanation:
Given:
v₀ = 0 m/2
v = 12 m/s
t = 6 s
Find: Δx
Δx = ½ (v + v₀) t
Δx = ½ (12 m/s + 0 m/s) (6 s)
Δx = 36 m
The track is 100 m, so the sprinter still has to run another 64 m.
Answer:
The magnitude of buoyancy force is equal to that of ball's weight.
Explanation:
Ball 1 is floating on water. Weight of ball 1 is Fg=m1g is acting vertically downward
Force of buoyancy FB = ρVdisg is acting vertically upward.
Net force acting on the ball is zero, FB=Fg
Answer
The magnitude of buoyancy force is equal to that of ball's weight.
I believe it's B. the transmission of heat across matter
