37 Questions - All Questions Are Required

Physics

2 answers:

Ahat [919]3 years ago

6 0

A= dv / dt
a= (22 - 10)/3
a= (12)/3
a= 4 m/s²

ANTONII [103]3 years ago

5 0

Acceleration = vf-vi /t
10-22/3=2.6m/s^2

You might be interested in

A child of mass 40.0 kg is in a roller coaster car that travels in a loop of radius 7.00 m. at point a the speed of the car is 1

pav-90 [236]

I attached the missing picture.
The force of seat acting on the child is a reaction the force of child pressing down on the seat. This is the third Newton's law. The force of a child pressing down the seat and the force of the seat pushing up on the child are the same.
There two forces acting on the child. The first one is the gravitational force and the second one is centrifugal force. In this example, the force of gravity is always pulling down, but centrifugal force always acts away from the center of circular motion.
Part A
For point A we have:
$F_a=F_cf-F_g$
In this case, the forces are aligned, centrifugal is pointing up and gravitational is pulling down.
$F_a=m\frac{v^2}{r}-mg=179 $N$
Part B
At the point, B situation is a bit more complicated. In this case force of gravity and centrifugal force are not aligned. We have to look at y components of this forces, y-axis, in this case, is just pointing upward.
$F=F_{cf}\cos(30)-mg=m\frac{v^2}{r}\cos(30)-mg=153.2$N$
Part C
The child will stay in place at point A when centrifugal force and force of gravity are in balance:
$F_g=F_{cf}\\
mg=m\frac{v^2}{r}\\
gr=v^2\\
v=\sqrt{gr}=8.29\frac{m}{s}$

6 0

3 years ago

Extend your thinking: household appliances are usually connected in a parallel circuit. why do you think it might be a problem i

alexandr1967 [171]

The equivalent resistance of several devices connected in parallel is given by
$\frac{1}{R_{eq}} = \frac{1}{R_1}+ \frac{1}{R_2}+...+ \frac{1}{R_n}$
where $R_i$ are the resistances of the various devices. We can see that every time we add a new device in parallel, the term $\frac{1}{R_{eq}}$ increases, therefore the equivalent resistance of the circuit $R_{eq}$ decreases.

But Ohm's law:
$I= \frac{V}{R_{eq}}$
tells us that if the equivalent resistance decreases, the total current in the circuit increases. The power dissipated through the circuit (and so, the heat produced) depends on the square of the current:
$P=I^2 R$
therefore if there are too many devices connected in parallel, this can be a problem because there could be too much power dissipated (and too much heat) through the circuit.

6 0

3 years ago

A. If a T-Rex runs 20 meters in 4 seconds, what is it’s average speed?

mariarad [96]

5m/s

100m

Explanation:

Average speed is sum of distance distance traveled in a given time by a body.

Average speed= $\frac{total distance covered}{time taken}$