Bala temana ye ka šedi gore o tle o akaretše ka mantšu a gago o šeditše dintlhа tše bohlokwa/dikgopolokgolo mabapi le Kamano ya segwera le mogofe, go ya ka ditaelo tše di latelago:

Convert time to seconds:

$$t = 7 \times 60 = 420~\mathrm{s}$$

Distance formula for constant acceleration:

$$s = ut + \frac{1}{2}at^2$$

where $u=10~\mathrm{m/s}$, $a=1~\mathrm{m/s^2}$, $t=420~\mathrm{s}$.

Substitute values:

$$s = (10)(420) + \frac{1}{2}(1)(420)^2$$ $$(420)^2 = 176400$$ $$s = 4200 + \frac{1}{2}(176400)$$ $$s = 4200 + 88200$$ $$s = 92400~\mathrm{m}$$

92400 m

Speed formula:

$$v = u + at$$

Substitute values:

$$v = 10 + (1)(420)$$ $$v = 10 + 420$$ $$v = 430~\mathrm{m/s}$$

430 m/s

Distance formula:

$$s = ut + \frac{1}{2}at^2$$ $$700 = (10)t + \frac{1}{2}(1)t^2$$ $$\frac{1}{2}t^2 + 10t - 700 = 0$$

Multiply by 2:

$$t^2 + 20t - 1400 = 0$$

Quadratic formula: $t = \frac{ -20 \pm \sqrt{20^2 - 4(1)(-1400)} }{2}$

Discriminant:

$$400 + 5600 = 6000$$ $$\sqrt{6000} = \sqrt{400 \times 15} = 20\sqrt{15}$$

Positive root:

$$t = \frac{ -20 + 20\sqrt{15} }{2} = -10 + 10\sqrt{15}~\mathrm{s}$$

-10 + 10\sqrt{15} s

Speed formula:

$$v^2 = u^2 + 2as$$ $$v^2 = (10)^2 + 2(1)(700)$$ $$v^2 = 100 + 1400$$ $$v^2 = 1500$$ $$v = \sqrt{1500} = \sqrt{100 \times 15} = 10\sqrt{15}~\mathrm{m/s}$$

10\sqrt{15} m/s

First, final speed $v$ at $s=860~\mathrm{m}$:

$$v^2 = u^2 + 2as$$ $$v^2 = 10^2 + 2(1)(860)$$ $$v^2 = 100 + 1720$$ $$v^2 = 1820$$ $$v = \sqrt{1820} = \sqrt{4 \times 455} = 2\sqrt{455}~\mathrm{m/s}$$

Average speed:

$$v_\mathrm{avg} = \frac{u + v}{2}$$ $$v_\mathrm{avg} = \frac{10 + 2\sqrt{455}}{2}$$ $$v_\mathrm{avg} = 5 + \sqrt{455}~\mathrm{m/s}$$

5 + \sqrt{455} m/s